#include <bits/stdc++.h>

using namespace std;

const int N = 500005;

int n, lst[N], fenw[N];

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tt;
  cin >> tt;
  while (tt--) {
    int m;
    cin >> n >> m;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      --a[i];
    }
    vector<int> xs(1, 1);
    for (int i = 0; i < n; i++) {
      xs.push_back(a[i]);
      xs.push_back(a[i] + 1);
    }
    sort(xs.begin(), xs.end());
    xs.erase(unique(xs.begin(), xs.end()), xs.end());
    int k = (int) xs.size();
    for (int i = 0; i < n; i++) {
      a[i] = (int) (lower_bound(xs.begin(), xs.end(), a[i]) - xs.begin());
    }
    vector<vector<int>> pos(k);
    for (int v = 0; v < k; v++) {
      pos[v].push_back(-1);
    }
    for (int i = 0; i < n; i++) {
      pos[a[i]].push_back(i);
    }
    for (int v = 0; v < k; v++) {
      lst[v] = -1;
    }
    vector<vector<pair<int, int>>> qs(n);
    for (int v = 0; v < k; v++) {
      pos[v].push_back(n);
      int sz = (int) pos[v].size();
      for (int j = 0; j + 1 < sz; j++) {
        int L = pos[v][j] + 1;
        int R = pos[v][j + 1] - 1;
        if (L <= R) {
          qs[R].emplace_back(L, -(xs[v] + 1));
        }
      }
    }
    vector<int> fenw(n + 1);
    auto Modify = [&](int p, int x) {
      for (p++; p <= n; p += p & -p) { 
        fenw[p] += x;
      }
    }; 
    auto Query = [&](int p) {
      int res = 0;
      for (p++; p; p -= p & -p) {
        res += fenw[p];
      }
      return res;
    };
    int ans = -1;
    for (int i = 0; i < n; i++) {
      if (lst[a[i]] != -1) {
        Modify(lst[a[i]], -1);
      }
      Modify(i, +1);
      lst[a[i]] = i;
      for (auto& p : qs[i]) {
        ans = max(ans, Query(i) - Query(p.first - 1) + p.second);
      }
    }    
    cout << ans << '\n';
  }
  return 0;
}